Got the dreaded code 69 this past week, temp has been running about 1/4th on the gauge the past few days. Already had a new t-stat on hand with o-rings, so dived into it this morning. Total R&R time was about 1.5 hours, had to run out and get some distilled water to mix with the coolant. Only took apart things absolutely necessary, which seemed to make the job go easier. Replaced one of the big o-rings, which had a couple indentations on it. Re-used the other large one and the small ones. So far looks like everything is fine. It's a little tricky getting the housing out, but this job really isn't very difficult. It was easier for me to put the housing back in versus getting it out. The car has 99k miles on it, I assume it was the original t-stat.